Rescuers travelled on foot to reach the chopper's wreckage spotted on a forested hillside in neighbouring Nuwakot district.

An American trainer working with Saudi Arabia' National Guard was killed on Thursday in a helicopter crash in Riyadh in the course of a routine activity, a statement published by state media said.

A helicopter crash in northern Afghanistan on Sunday killed at least three people including a foreign pilot, Afghan officials said.

Australian Associated Press reported that the aircraft, a 1994 Kawasaki BK117, had crashed into a tree.

Eighteen people were killed in a helicopter crash in the Krasnoyarsk region in Siberia on Saturday, the aviation watchdog and emergency services said.

At least three people were killed in a helicopter crash in northeastern Thailand on Wednesday, officials said.

A Russian helicopter crashed in Syria late on Monday killing both pilots, Moscow's defence ministry said in a statement carried by news agencies.

A Russian military helicopter has crashed during a training night flight over the Baltic Sea, killing two pilots, the Russian army said on Friday.

At least 13 people on the ground, including three children, were killed when a Mexican military helicopter carrying top officials surveying damages from an earthquake crashed in a small town in the southern state of Oaxaca, authorities said on Saturday.

Searchers have recovered two more bodies from the wreckage of a helicopter that crashed off India's west coast, taking the death toll to six, an official said Sunday.

India's coast guard said four bodies had been recovered on Saturday after search teams located the wreckage of a helicopter that went missing earlier in the day.

A Saudi prince was killed on Sunday when a helicopter with several officials on board crashed near the kingdom's southern border with war-torn Yemen, state television said.